Method of manufacture for slide fasteners



Oct. 30, 1951 A. e. WERY 2,573,17I

METHOD OF MANUFACTURE F OR SLIDE FASTENERS Filed July 18, 1947 Patented Oct. 30, 1951 METHOD OF MANUFACTURE FOR SLIDE FASTENERS Albert G. weryg Teaneck, N. J., assignor to Rex Slide Fastener Corporation, New York, N. Y., a corporationof-New York Application July 18, 1947, Serial No. 761,770

1 Claim.

I This invention'relates to'a method of manufacture for slide fasteners.

In one of the many methods followed in manufacturing slide fastener elements, in order to facilitate attachment of the elements to the cloth tape, it has been found desirable to break up the operation of forming elements from metal lic stock into a number of separate steps. In one of these methods, impressions are made in metallio stock, which may'take theform of wire or strip, to preform parts of the elementas a separate operation. This operation may be effected by rolling or otherwise pressing the wire or strip.

Where this step of preforming involves rolling, factors are encountered which limit the efficiency of the operation. For instance, when strip or wire is passed between coining rolls, the metal flows and is squeezed in all directions. The purpose of the operation, however, is to produce the complementary recesses and projections which are the essential parts of a slide fastener element. To provide therequired contours for rolls to produce'these complementary projections and recesses presents a problem where parts of the rolls are not alike but intermesh much as if they were a pair of gears. The rolls may be considered to .cooperate with the formed member in a manner similar to the cooperationof a gear with a rack, or a pinion gear with an annulargear; But the analogy is notcorrect. For the metal being rolled does not retain its original form, as does a gear.

, After the projections and recesses have been formed in the wire by the action of the rolls; those recesses and projections'of the rollsassos ciated with the projections and recesses "in'the wire must release from each other without'deforming the formations already imparted to'the wire. Certain minimum requirementsof slope of surface, width of projection, and depth of recess, necessary for a properly formed fastener element, determine the" necessary design for the rolls to produce that result.

These considerations have made it-desirable to reduce the size of the rolls used for this purpose, and thereby to assure effective release of the forming surfaces of the rolls from theformed portions of the metallic member being worked without possible undesirable distortion of the formed portions. By such means, the effective surface in working contact with the wire is reduced. jSuch reduction of diameter, however, necessarily entails sharp reduction in the number of impressions for slide'fastener elementswhlch may be produced for eachv rotation, of ,the-rolls.

This, in turn, increases the work which must be done by each of the identical forming recesses or projections of the rolls in any unit of machine time operation. Obviously, the life of the forming portions of the roll suffers out of proportion with the increased work required. Any defect which develops in any one of the forming portions precludes further use of that roll.

It is an object of the invention to provide apparatus for, and a method of, making preformed stock for slide fastener manufacture, whereby rolls of substantial diameter may be utilized, and yet withoutthe dangers of deforming a preformed portion of a fastener element.

To use rolls of relatively large diameter, and simultaneously to protect the elements after their formation has been completed, requires a change in the method of release of the formed portions of the metallic stock from the rolls. It is an object of the invention so to direct the stock, after it has been worked by the rolls, that it is released substantially completely from one of the rolls before its release from the other roll is commenced to any degree, and in any case before it is completed. The precision of rolling gear teeth is not suitable even theoretically for the formed members necessary for slide fastener manufacture, since the surfaces necessary for such purposes, because of the manner in which slide fasteners operate, do not respond to the usual formulae of gear teeth. The particular form usual for slide fastener elements includes a frontal cam face, and a fairly steep locking face. In order to form such units by rolls of large diameter, it is an object of the invention to release one side of the formed stock from one of the rolls which produced them without causing that roll further to work the metal, and thereafter, when the worked stock is no longer in position to be worked by the first roll, to release the other side of the worked stock from the other roll.

It is an object of the invention so to direct the stock that, after the forming operation has been completed, the formed stock remains substantially snugly engaged with the forming portions of one of the rolls until the formed face of the stock juxtaposed to the face so engaged moves completely away from the other roll which formed it; then, when this step of separation of the stock from that roll has been completed, the separation of the formed stock from the forming rolls is completed as a gradual stage beyond the forming position.

It is an object of the invention to provide a method; of preforming wire for ,slide fastener:

manufacture, and apparatus therefor, wherein, although the theoretical number of forming surfaces of at least one of the rolls in contact with the stock is increased by use of rolls of large diameters, the effective number of surfaces of the rolls simultaneously in engagement with the wire is such as to be-comparable with ,thatof --rolls f much smallerzdiameter.

Other objects of the invention will be set forth hereinafter, or will be apparent from the description and the drawings, in which are illustrated embodiments exemplifying the invention.

The invention, however, is not intended to be restricted to any particulareonstructiom-or-any particular arrangement of parts, or;any;particular application of any such construction or arrangement of parts, or any specific method .of operation or use, or any of the various details thereof, even where specifically shown amidescribed herein, as the same may be modified in various particulars, or :may v.be applied inmany {varied relations, without departing from .the spirit and scope of the claimed invention, of which the exemplifying embodiments, herein shown and described, are intended only ,to ,be

illustrative, and-only for-the purposeofcomply- ,ing w-ithrtherequirements of .the statutes fondisclosure of :an {operative embodiment, .but not ..to show-:all't-he variousformswand modifications in which the inventionrmight be-embodied.

,On ,the drawings, in which the samereference characters refer to-the same parts throughout, and .in whicheare disclosed such practical .constructions,

-.Eig.,1 is a view in elevation, illustratinga rolling'operationof ,the old tart, parts :being broken awayain sectionand ,parts being broken away .to clarify the disclosure;

Fig. 1a is aview to enlarged'scale of a portion of Big. ,1, illustrating \the action-of the rolls'on the metal being worked;

Fig. 2 is a view. similarto, Fig. ,1, illustratingan application of the invention .to the process of rolling, the normalposition of the fed wire .being shown bydot-and-dash lines;

, (Fig. 3 .is a viewsimilarto -Figs..1 and ,2, illustrating another modification of the invention; and

AFigaA .is a transverse vertical cross-sectional view through ,a wire or strip of .modified .form

for use in rolling metalior slide fastener .ele-

merit manufacture.

In Fig. '1, thereds illustrated apparatus for,.rolling ordinary stock of substantially cylindrical cross-section, suchas wire orstrip, by means of a pair of rolls of small diameter vto preform the stock, for use in slide fastener manufacture. Stock, such .as round wire 18, "is fed between driven, oppositely rotating rolls ,I2 and I4. Guides [6, provided at the entering side It of the rolls-direct the wire substantially tangentially to the working surfaces of --the two -rolls at the position where the rolls "are effectively tangentially disposed to each' other as at point 20, where the line of centers of the -two rolls passes. On the dischargeside 22 of the rolls, preformed wire 24 moves away fromthe'rolls; -'it maybe reeled up, or otherwise utilized. By the forming operation effected 'by -rolls l2 and 14, projections or pins 26, with complementary =recesses or cups 28, are formedon the wire. For illustrative purposes only, roll 42 may be considered to -have forming indentations 30, while roll [4 has forming projections 32. ":By suitable means, 'includinga geartrain -34,-the two rolls are driven Y in opposite' directions an'd 'with equal =atposition20, engaged against face 38 of pin 26.

In like manner, face 40 of projection 32 is engaged against wall 42 of cup 28. If the diameters 14 .are properly related, wall 36 and face 4|] 'will not have a tendency to drive the metal of the wire by engagement against face 38 x and-.wall'42. When the diameters of rolls l2 and -l 4 are small, this result ensues as the roll portionsseparate rapidly from the formed portions of the wire for which those roll portions have been responsible. Likewise, as shown in Fig. 1, the angle 44 subtended by the arcs of both rolls where in contact with metal being worked includes but a: small number of projections ,32 crindentations 3U.

,Whenthe roll diameters are large, portions such as projections 32, which function to draw the metal ;and drive it out of original form of the stock, necessarily have a peripheral speed with relation to the metal being formed higher than that of portions such as indentations 30. Thus, the escaped the metal, after being formed, from the 'working surfaces may, in .many cases, beleffected, in the ordinarymethods of rolling, only-withzadditional working at a position where undesired, with resultant distortion of the product.

IniE'ig. 2,1the structure, to illustrate theinvention, has rolls 4B and 48 of any suitable large diameter to obtain a preferred number of preforming projections and indentations far in excess of the number on small rolls. Forinstance, rolls threevand four :times the usual diameters maybe-used. ":Rollc46 is shown with indentations 5'0- for forming pins 26, and roll 48 has projections M ter-forming cups 28. Guides 54 are arranged re atively'toithe portionof wire I0 being fed up to and thenibetween the-rolls. Guides 54 ma be positioned to feed the wire tangentially to both IO11S346 and 48 simultaneously, that is, substantial y perpendicularly to the line of centers of both rolls. 'In relation to the working'step effected, and theseparating ste to be effected, guides '54 are disposed so that the wire approaches position 20 at an angle away from the perpendicular'to the'line of centers. In this case, the wire is'ledlby guides "54 so that it is tangential on1y' to:rolle46,but that point of tangency is in advance of point where the'line of centers passes. ASFShOWllilIl Fig.2, therefore, section 560i wire IMwrapsitself-against r011 46 for a limited arc uptto position 20. For certain purposes, the wire may be brought up to the rolls biased on-the opposite angle;bearingagainstroll 48 rather than roll 46. By either arrangement, the working-faces of one roll perform someof their drawing action on one side of-the-wire before the rolls joinin their :action to complete the preforming of the wire.

-:At-.withdrawing position 58 are guides 60 which assure'that preformed wire 24 moves away from position'zfl tangentially to but one of the rolls. In :this case, the withdrawing operation is car- 'rie'd' 'outso that preformed wire 24 moves-away from roll 46,'and follows roll 48 around its'periphery' for ashort arcuate :distance. As shown in Eig.-'. 2,'--cups 28 "hu projections *52' on roll- 48. As ithe wire moves -towards guides 'fiflypins' zfis-on the preformed wire are relieved gradually from engagement within indentations 50, but cups 28 still remain substantially completely engaged upon projections 52. Thus the tendency that the wire itself be driven along by further engagement of the roll face against the wire, and, therefore, with continued working of the metal at position 20, is counteracted.

The wire, being restrained by guides 60, and after pins 26 are substantially relieved from engagement with indentations 56, now moves, at position 53, to separate from projections 52. When the wire has reached position 58, the possibility of forming present at position 20 has been dissipated; the wire is now ready for slow release from roll 48 and its projections without interference from roll 46. Guides 60, illustrated in Fig. 2, are set at such an angle that the line of feed thereto is at an angle to the perpendicular to the line of centers of the two rolls, and is tangential only to roll 48, but at a point beyond the forming position. This location causes cups 28 to move free of projections 52 without working of the metal at position 58, the worked portions of the wire at that position having no engagement at all with the surfaces with which they were in contact during the forming oper-' ation.

The previous description is of one method of timing the separation of the formed faces of the wire separately from the two rolls. However, it is believed to be more desirable that the guides be positioned so that the formed face of the wire releases from roll 48 before it moves free of roll 46. This follows from the disposition of the working projections 52 with relation to the cups 28 formed in the preformed wire. It is much simpler to release in this manner, as shown in Fig. 3. Guides 62, which may be of the same structure as guides 60, are disposed so that the wire moves angularly away from forming position 2!], rather than perpendicularly to the line of centers of the rolls. The wire hugs roll 46, with its pins 26 seated in indentations 50, until it has substantially completed its release from roll 48. Then release of the wire at or beyond the new separating position 64 is effected by slow movement of pins 26 out of indentations 50.

Further to facilitate the operation, wire I'D may be preformed before the rolling steps just discussed. For instance, the stock may be rolled, drawn or otherwise formed to impart to it a section 66 for the specific purpose of facilitating the formation of projections or pins 26. In all such cases, the rolling operation effects the flattening of the wire, as well as the formation of pins and cups therein. Such preforming is designed to provide additional metal Where it is required for the formation of the pins. Qbservation of the results of rolling operations shows that the flow of the metal is not completely effective consistently to force metal up into indentations 30 or 50. Sufficient metal must be positioned to cooperate with the indentations to assure that working of the metal will not depend merely upon flow of metal into the indentations, but that it will follow from flow of the metal away from raised portions of the roll beyond the indentations. With preformed wire of this type, the separation of the preformed wire from the rolls will be effected substantially in the same manner as heretofore described.

Many other changes could be effected in the particular constructions, and in the methods of use and construction, and in specific details thereof, hereinbefore set forth, without substantially departing from the invention defined in the claims, the specific description being merely of embodiments capable of illustrating certain principles of the invention.

What is claimed as new and useful is:

In a method of producing, in a metallic member of substantially uniform cross-section, a plurality of connected substantially identical successive reproductions of the pin and cup of an element of a slide fastener, the pins and cups being dimensioned for interlocking engagement, the steps of passing the metallic member between forming rolls one of which has raised projections for forming the cup and the other of which has recesses for forming the pin, and withdrawing the preformed member from between the rolls along a path substantially following the periphery of the roll having the projections so that the pins formed in the indentations in the one roll release from those indentations while the cups continue to remain engaged against the projections of the other roll for a portion of its contour beyond the forming position.

ALBERT G. WERY.

REFERENCES CITED The following references are of record in the file of this patent:

V UNITED STATES PATENTS Number 

